Islamabad, Feb 18 (IANS): Two polio workers and two security guards, who went missing a week ago, have been found shot dead in Pakistan, media reported Wednesday.

"The bodies of two polio workers and two Levies personnel were found in the mountainous area of Killi Murgha Kibzai, in Bolachistan province" Dawn reported cited a senior official of Zhob administration as saying Tuesday.

The four had gone to a village close to Afghan border for administrating anti-polio drops to children, but did not return to their homes.

"They could not be traced till Monday night," security officials said.

No one has claimed responsibility for the killing, but sources believe that members of the Tehreek-i-Taliban Pakistan kidnapped them.

Security forces launched a search operation in Murgha Kibzai Sunday and cordoned off a place, but two men wearing suicide jackets blew themselves up when security forces tried to arrest them.

Six suspects were arrested, but the polio workers and Levies personnel were not found.

The sources said that local people informed the authorities that four bullet-riddled bodies with marks of torture had been dumped in Murgha Kibzai area. Security forces rushed to the place and took the bodies to the district hospital in Zhob.